The invention relates generally to a repair circuit using an antifuse, and more particularly to, an antifuse repair circuit having a special address multiplexer for repairing defective cells.
A conventional repair technology employs a laser repair method by which a poly fuse is blown by lasers in the state of a wafer. The packaged memory devices experience a final test, which is performed after a burn-in stress is applied. The test shows that about 5% to about 15% are defective. As the products are packaged, however, it is impossible to use a laser repair method. In order to reduce these defective products, a repair technology using an antifuse has been developed. In order to implement this antifuse, every antifuse in the antifuse box requires a specific address. As the antifuse is programmed one by one, many addresses must be decoded in order to implement a specific address.
However, as one antifuse box includes 22 (twenty-two) fuses, the number of fuses becomes very great. As a result, there is a problem in manufacturing a memory chip since a large number of address pins must be added.